The invention relates generally to agricultural implements and, more specifically, to a method and apparatus for creating a pass marker in row crops to assist in application of agrochemicals and harvesting of the crop.
In many parts of the world, crops are planted in equally spaced rows with large agricultural planters. These equally spaced rows make it convenient for spraying, fertilizing, or harvesting with standard sized equipment. Since the advent of planting crops in rows, farmers have struggled to drive into the correct row of the next pass when turning around. Finding the right row is important because driving down the wrong row produces yield limiting overlaps or skips when applying pesticides and fertilizers.
Counting rows is a common method to find the next pass, but counting accurately is difficult when turning around a 30-foot or 40-foot machine. It becomes more difficult as machine size and swath widths become larger. There are many sprayers that have 80-, 90-, or even 120-foot booms which make even more rows to count. Variation in crop type, crop height, terrain, wind and lighting conditions can also make counting rows difficult.
The problem is also evident when harvesting corn. Many large farming operations now use grain carts and harvest fields in ‘lands.’ The combine operator strikes through the field in certain spots so they can harvest with their unloading auger always on the harvested side of the field and harvesting in a counter-clock-wise motion. This allows the grain cart to stay close to the combine allowing for more efficient harvesting. When a land is finished, the combine operator then proceeds to strike across another portion of un-harvested crop. The operator usually needs to count rows in multiples of their corn head size so all passes utilize the full width of the head. There are instances where an operator loses count or miscounts and the last pass is either very small (1 or 2 rows) or short of the full width (7 rows on an 8 row head or 11 rows on a 12 row head).
Companies and farmers have tried many solutions to finding the correct row. One method is to predict where to turn back into rows using a GPS navigation display. This feature is known as RowFinder feature. The GPS navigation display will record the current position/heading of the vehicle at the end of a pass, and graphically show where to turn to enter the next pass. The user tries to manually steer the vehicle into the correct row based on the machines location relative to an indicator on the navigation computer screen. However, an expensive high accuracy GPS is required and manually steering into the correct row using a computer screen indicator is difficult to do accurately. It becomes more difficult in crops planted in narrow row spacing, such as 20 or 30 inches. Additionally, GPS assumes all rows have the same spacing, but that is often not the case on a so-called planter guess row which is the row space between the outside rows of adjacent planter passes. Guess row spacing is dependent on driving accuracy relative to the adjacent pass. Row spacing between all other planter rows are fixed because planter row units are mounted to the planter frame at a fixed spacing.
A variation of the RowFinder feature is called iTEC Pro (intelligent Total Equipment Control) by Deere and Company. By using vehicle controller information paired with high accuracy GPS coordinates, this system actually turns the tractor around automatically at the end of the field. The user does not turn the steering wheel at all during the process. While convenient and very accurate, this method is expensive and only compatible with the newest tractors and equipment. It also does not account for variation in planter guess row spacing.
Another prior art is planting a unique variety, or pass marker variety, in rows that subsequent machines will use to locate their passes. The problem is the pass marker variety is not always distinguishable from the variety of adjacent rows. Further, the pass marker variety may not yield as much as the desired variety. It also creates slower planter fill times compared to one variety in all rows.